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    <script>
        // 2.用函数方法实现数组反转[1, 2, 3, 4]=> [4, 3, 2, 1]
        function contraryArr(arr){

            let newArr = []
            for(let i = arr.length - 1; i >= 0; i--){
                newArr[newArr.length] = arr[i]
            }
            return newArr
        }

       console.log(contraryArr([1,2,3,4,5]));


    </script>

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